* Programs that run on Linux should generally also run on any Unix system.

Tcl/Tk

Programs using Tcl/Tk are developed on Linux, but also tested on
Windows. Those programs should generally run on any operating system that is
supported by Tcl/Tk. This includes MacOS and most Unix flavors. Tcl/Tk is
part of every serious Linux distribution and in most cases already installed
on commercial Unix systems. So generally only Windows users need to download
it.

zip

My Tcl/Tk programs are distributed as ZIP files, because they are easier to
unpack on Windows. On Linux use unzip or doubleclick on the file in
your Gnome or KDE filemanager. On Windows I recommend to use PowerArchiver.

sh

Programs using sh are developed on Linux, but should run on any Unix system or
Windows with GNU Win32. sh is the original Unix shell present on every even
very old Unix system.